On Mon, Jun 15, 2009 at 01:53:13PM -0400, Bill Nottingham wrote: > Way back when in February [1], FESCo decided that for Fedora 11, i586 would > be the default architecture, and for Fedora 12, it would be some variant of > i686. It's time to follow through on that action item. > > I've submitted https://fedoraproject.org/wiki/Features/F12X86Support. It > defines the default arch as i686 + SSE2. > > Why? > > - Faster and more consistent FP math by using SSE2 registers > - Allows for autovectorization by GCC where necessary > - More clearly delineates our support set of targets, sticking true > to forwards innovation, not necessarily legacy support > > What CPUs do we lose that F11 supports? > > - Intel i586 (all) judging by the number of 586 users who register with smolt (less than 0.1% our entire userbase), not that big a deal. > - Intel Pentium Pro > - Intel Pentium II > - Intel Pentium III > - 32-bit AMD Athlon These are more of a concern. It's difficult to tell from smolt just how big a deal these are. P3 & Athlon especially. I poked Mike privately in the hope that we're gathering enough of /proc/cpuinfo that we can perhaps get some info on how much our userbase we'd be shutting off. I still have two machines that would be affected (one in actual production use as a backup server, the other just a testbox which is tbh rarely powered on) and I'm not even a good representation of our userbase (I ditched all my ancient junk a while back). > - VIA C3 Some of the later C3's have SSE2, so wouldn't be affected. > - AMD Geode > - Transmeta Crusoe Running the shiny latest bits on these CPUs means you're already used to living with pain, so a secondary arch seems like the way forward. > Does this lose the PAE/non-PAE kernel split? > > - Alas, no. > > Will a Fedora rebuilt in this manner work on ... > > - OLPC 1.0? No. > - OLPC 1.5? Yes. > - Atom? Yes. > > A seconday arch could be done for these older CPUs, if someone is interested > enough. > > Comments? Flames? Predictions of doom? If we 2nd-arch these, I'm wondering if we should still do the kernel builds from the main package. If it's a significant number of users, we're going to end up with the bug reports anyway so it might as well be something we know we built etc.. Dave -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
